Graft polymers of ketone-aldehyde condensation and co-condensation products

ABSTRACT

Graft polymers of ketone-aldehyde condensation and co-condensation products and/or the monovalent or polyvalent metal compounds thereof are described, in which condensation product consists 
     a) of symmetrical or asymmetrical ketones containing aliphatic, araliphatic, cyclic or aromatic hydro-carbon radicals with at least one nonaromatic radical, 
     b) an aldehyde of the formula R--(CHO) n , wherein n=1 to 2 and R can be hydrogen or an aliphatic, araliphatic, aromatic or heterocyclic radical, and 
     c) optionally of carboxyl, sulpho, sulphamido, sulphoxy, sulphoalkylamine or sulphoalkyloxy groups, 
     to which product anionic and/or nonionic and/or cationic unsaturated monomers have been grafted. These graft polymers are outstandingly suitable as dispersants for inorganic binder suspensions and solutions, for aqueous clay suspensions and solutions or coal/water suspensions, as retention agents, thickeners, in particular for aqueous systems, and as agents for preventing the swelling of clay in aqueous systems.

BACKGROUND OF THE INVENTION

The present invention relates to graft polymers of ketone-aldehydecondensation products and co-condensation products and/or the monovalentor polyvalent metal compounds thereof, the preparation thereof and theuse thereof.

Ketone-aldehyde condensation and co-condensation products have long beenknown. Thus, readily water-soluble condensation products ofcycloalkanones and formaldehyde, with the use of sodium sulphite as asubstance introducing acid groups, are described in, for example, GermanAuslegeschrift 23 41 923. However, a serious disadvantage of thesecondensation products is their low thermal stability, with the resultthat their range of uses is greatly limited.

Good thermal stability is a property of the acid group--containingcondensation products of aldehydes and ketones according to GermanOffenlegungsschrfit 31 44 673 and co-condensation products according toGerman Offenlegungsschrift 33 15 152 and the metal compounds of these(co-)condensation products according to German Offenlegungsschrift 34 29068. Although these products can be used as thickeners, retentionagents, surfactants, dispersants or liquefying agents for aqueoussystems, the relevant product properties are not optimum in some fieldsof use.

It was therefore the object of the present invention to modify theketone-aldehyde condensation, and co-condensation products and the metalcompounds thereof, respectively, in such a way that the technicalapplication properties of the. corresponding derivatives are furtherimproved.

THE INVENTION

This object was achieved, according to the invention, by this provisionof graft polymers of ketone-aldehyde condensation and co-condensationproducts, respectively, and/or the monovalent or polyvalent metalcompounds thereof, which are characterized in that the condensationproduct consists

a) of symmetrical or asymmetrical ketones containing aliphatic,araliphatic, cyclic or aromatic hydrocarbon radicals with at least onenonaromatic radical,

b) an aldehyde of the formula R--(CHO)_(n), where n=1 to 2 and R can behydrogen or an aliphatic, araliphatic, aromatic or heterocyclic radicaland

c) optionally of acid groups, preferably carboxyl, sulpho, sulphamido,sulphoxy, sulphoalkylamine or sulphoalkyloxy groups,

to which product anionic and/or nonionic and/or cationic unsaturatedmonomers have been grafted.

It has in fact surprisingly been found that the properties can beinfluenced in a specific manner by grafting the relevant unsaturatedmonomers onto the (co-)condensation products and the metal compoundsthereof, respectively.

The parent structures of the graft polymers according to the inventionconsist of ketone-aldehyde condensation and co-condensation products,respectively, and/or the monovalent or polyvalent metal compoundsthereof, as described, for example, in German Offenlegungsschrift 31 44673, German Offenlegungsschrift 33 15 152 or German Offenlegungsschrift34 29 068. The ketones used here are symmetrical or asymmetricalcompounds containing aliphatic, araliphatic, cyclic or aromatichydrocarbon radicals with at least one nonaromatic radical, the totalnumber of carbon atoms and hetero atoms in the ketones preferably being3 to 12. Suitable aliphatic radicals are straight-chain or branched,unsaturated and, preferably, saturated alkyl radicals, such as, forexample, methyl, ethyl, propyl, isobutyl, etc. Araliphatic radicals are,for example, benzyl or phenethyl, and aromatic radicals are, forexample, α- or β-naphthyl and preferably phenyl.

The ketones can also have one or more substituents, such as, forexample, amino, hydroxyl, alkoxy, acetyl or alkoxycarbonyl groups.Examples of ketones containing saturated aliphatic radicals are acetone,methyl ethyl ketone and methyl isobutyl ketone, examples of ketonescontaining substituted aliphatic radicals are methoxyacetone, diacetonealcohol and ethyl acetoacetate, examples of ketones containingunsaturated. aliphatic radicals are methyl vinyl ketone, mesityl oxideand phorone, an example of a ketone containing araliphatic radicals isbenzylacetone, examples of ketones containing cyclic radicals arecyclohexanone and cyclopentanone, and examples of ketones containingaromatic radicals are acetophenone and 4-methoxyacetophenone.

Suitable aldehydes of the formula R--(CHO)_(n) are those compounds inwhich n is 1 to 2 and R is hydrogen or an aliphatic, araliphatic,aromatic or heterocyclic radical, the total number of carbon atoms andhetero atoms preferable assuming a value of 1 to 11. Aliphatic radicalsare, in particular, alkyl radicals, preferably having 1 to 6 carbonatoms, such as, for example, methyl, ethyl, propyl, butyl, etc. Thealiphatic radicals can also be branched or unsaturated (such as, forexample, vinyl). Aromatic radicals are, for example, α- or β-naphthyl,or phenyl, and heterocyclic radicals are, for example, furfuryl.

The aldehydes can also have one or more substituents, such as, forexample, amino, hydroxyl, alkoxy or alkoxycarbonyl groups and/or alsothe acid groups optionally contained in the condensation products.Aldehydes containing more than one aldehyde group, namely in particulardialdehydes, can also be used. It is also possible to use the lowersaturated, aldehydes, such as formaldehyde or acetaldehyde, in theirpolymeric form (paraformaldehyde or paraldehyde). Examples of aldehydescontaining saturated aliphatic radicals are formaldehyde (orparaformaldehyde), acetaldehyde (or paraldehyde) and butyraldehyde.Examples of aldehydes containing substituted saturated aliphaticradicals are methoxyacetaldehyde, 3-methoxyproptonaldehyde andacetaldol. Examples of aldehydes containing unsaturated aliphaticradicals are acrolein and crotonaldehyde. Examples of aldehydescontaining araliphatic radicals are phenylacetaldehyde andphenylpropionaldehyde. Examples of aldehydes containing aromatic orheterocyclic radicals are benzaldehyde, furfurol and 4-methoxyfurfurol.For example, glyoxal or glutardialdehyde can be used as dialdehydes.Formaldehyde is particularly preferably used as the aldehydes.

The relevant ketone-aldehyde condensation and co-condensation products,respectively, can optionally also contain acid groups, preferablycarboxyl, sulpho, sulphamido, sulphoxy, sulphoalkylamine orsulphoalkyloxy groups. An alkyl group in these radicals preferably has 1to 5 carbon atoms and is in particular methyl or ethyl. Preferablyinorganic acids such as amidosulfonic acid or their salts such as sodiumsulfite, sodium bisulfite and sodium pyrosulfite or organic acidsespecially carboxylic acids such as aminoacetic acid are used ascompounds introducing the acid group. The relevant condensation orco-condensation products can also contain two or more different acidgroups.

The molar ratio of compounds introducing ketones/aldehydes/acid groupscan be varied within wide limits and is, as a rule, 1:0.5 to 18:0 to 3.The co-condensation products, which are described in, for example,German Offenlegungsschrift 33 15 152, also contain, in addition to theketone, aldehyde and, optionally, the acid groups, 2 to 60% by weight,preferably 10 to 40% by weight, of a further component selected from

the group comprising aminoplast formers and/or aromatic compounds and/ora lignin and/or lignite derivative. All common nitrogen-containingcompounds, in particular those which are suitable for condensation withformaldehyde, can be used here as aminoplast formers, in particularurea, melamine, dicyandiamide or a guanamine (preferably acetoguanamineor benzoguanamine).

Phenols which are suitable for the formation of phenol resins, that isto say, in particular, phenol, cresols or xylenols, can preferable beused as aromatic compounds, but reactive substituted and/or polynucleararomatics, such as, for example, naphthalene and the derivativesthereof, may also be used. The aminoplast formers or aromatic compoundscan also be used completely or partially in the form of theirprecondensates or condensation products having different degrees ofcondensation. Aminoplast formers and aromatic compounds which containacid groups, such as, for example, naphthalenesulphonic acids, may alsobe used.

The lignite compounds used may be pure lignite, alkali-treated ligniteand/or sulphonated or sulphoalkylated lignite. For the purposes of thepresent invention, lignin compounds also include black liquors which areformed in the treatment of wood with sodium sulphite (sulphite process),but also ligninsulphonates and the formaldehyde resins thereof. Thelignins or lignites can also be used in the form of their metalcompounds (in particular iron and chromium).

Instead of the condensation and/or co-condensation products, it is alsopossible to use the monovalent or polyvalent metal compounds thereof, asdescribed in German Offenlegungsschrift 34 29 068. Metal compoundscontaining metals of groups II A to VIII A and/or of groups I B to V B(according to the definition of Kirk-Othmer, Encyclopedia of ChemicalTechnology, Interscience Publishers, New York-London-Sydney, 2nd Edition1965, Vol. 8, pages 94 to 96) are preferably suitable as metalcompounds, in particular the monovalent or polyvalent inorganic ororganic salts of these metals being used.

Examples of metal compounds are divalent or tetravalent manganese salts,divalent nickel salts, divalent or tetravalent lead salts, trivalent orhexavalent chromium compounds, divalent or trivalent iron compounds,trivalent aluminium compounds, monovalent and divalent copper compounds,divalent magnesium compounds and trivalent bismuth compounds. The amountof metal in these metal compounds is <70% by weight, preferably 0.1 to20% by weight. The preparation of these metal compounds is described inGerman Offenlegungsschrift 34 29 068.

It is regarded as essential for the invention that anionic and/ornonionic and/or cationic unsaturated monomers have been grafted ontothese relevant ketone-aldehyde condensation and co-condensationproducts, respectively, or the metal compounds thereof.

Vinyl compounds containing carboxyl, sulpho or phosphoric acid groupsare preferably used as anionic unsaturated monomers. Examples of suchunsaturated compounds containing carboxyl groups are acrylic acid,methacrylic acid, maleic acid, fumaric acid, iraconic acid and the saltsthereof. Examples of vinyl compounds containing sulpho groups arevinylsulphonic acid, allylsulphonic acid, methallylsulphonic acid,2-acrylamido-2-methylpropanesulfonic acid, styrenesulphonic acid and thesalts thereof. Examples of vinyl compounds containing phosphoric acidgroups are vinylphosphonic acid, 2-acrylamido-2-methylpropanephosphonicacid and methacryloxyethyl phosphate.

The anionic unsaturated monomer compounds can also be replaced bynonionic monomers, vinyl or acrylic derivatives being regarded aspreferred. In particular, N-vinylpyrrolidone, acrylamide,methacrylamide, N,N-dimethylacrylamide, acrolein, mesityl oxide, allylalcohol, acrylonitrile, vinyl acetate and styrene are used here. Furtherexamples of such unsaturated compounds are the esters of the abovementioned unsaturated acids.

Finally, it is also possible to use, for the grafting, cationicunsaturated monomers which are preferably quaternary ammonium compounds.Examples of such quaternary ammonium compounds aremethacryloyloxyethyltrimethylammonium chloride (METAC),(meth)acrylamidopropyltrimethylammonium chloride (MAPTAC),trimethylallyloxyethylammonium chloride (TAAC) anddimethyldiallylammonium chloride (DMDAAC).

The weight ratio of ketone-aldehyde condensation or co-condensationproduct to unsaturated monomer can be varied within wide limits, but ithas proved particularly advantageous to adjust this ratio to 1:0.02 to10. The procedure of the grafting reaction is relatively uncritical andcan be carried out by the customary known methods. The grafting reactionis preferably carried out in aqueous solution at a temperature of 0° to100° C. and at a pH of 1 to 13, the customary free radical initiatorsbased on redox systems, such as, for example, H₂ O₂ and iron(II) salts(such as, for example, iron(II) sulphate heptahydrate),peroxodisulphate/pyrosulphite or sulphite or cerium(IV) salts, orthermal initiators, such as AIBN or organic or inorganic peroxides,being relied upon.

After the grafting reaction has been carried out, which as a rule iscompleted after a few hours, the reaction solution is preferablyrendered neutral with the customary bases or acids. The graft polymersolution formed usually has a solids content of between 5 and 50% byweight.

Depending on the molecular weight and the type of unsaturated monomerused, the graft polymers according to the invention are suitable asdispersants, retention agents, thickeners and agents for preventing theswelling of clay. Suitable dispersants are, as a rule, graft polymers onthe basis of short-chain ketone-aldehyde condensation products having amolecular weight of <150,000 and having a high content of acid groupsand/or anionic monomers. It is critical here that the graft polymershave a negative overall charge. These graft polymers are outstandinglysuitable for dispersing inorganic binder suspensions or solutions, forexample for dispersing Portland cement, plaster or oil well cementslurries. These products are equally suitable for dispersing claysuspensions and solutions, as used, for example, in drilling fluids inthe form of bentonite suspensions.

If the graft polymers according to the invention are used on the basisof long-chain ketone-aldehyde condensation products having a molecularweight of >50,000 and the graft polymers having an anionic, nonionic orcationic charge, these products can be preferably used as retentionagents for aqueous systems. These products generally prevent the releaseof water from water-containing media, such as, for example, concrete,mortar, cement slurries, plaster and anhydrite slurries, clay slurries,etc.

The graft polymers according to the invention can also be used asthickeners, in particular for aqueous systems, if graft polymers on thebasis of very long-chain ketone-aldehyde condensation products having amolecular weight of >75,000 and the graft polymers having an anionic,nonionic or cationic charge are used. These products are very suitablefor increasing the viscosity of aqueous solutions or suspensions and canbe successfully used, for example, for thickening oil well cementslurries.

Finally, the graft polymers according to the invention can also be usedas agents for preventing the swelling of clay in aqueous systems, ifgraft polymers on the basis of short-chain to long-chain ketone-aldehydecondensation products having a molecular weight of 500 to 2,000,000 andthe graft polymers having a cationic or neutral charge are used. Theseproducts prevent, for example, the swelling of clays, such as, forexample, of drilled clay-containing solids in drilling fluids.

By varying the molecular weight and the type of charge, it is alsopossible, for the purposes of the present invention, to prepare productshaving combined properties.

The Examples which follow are intended to illustrate the invention inmore detail. Table 1 gives an overview of the starting material used inthe Preparation Examples.

                                      TABLE 1                                     __________________________________________________________________________    Synthesis Examples                                                                                                Co-condensation                                           Backbone Compound with                                                                            component or                              Example                                                                             Ketone    Aldehyde acid groups                                                                              metal compound                                                                         Graft monomer                    __________________________________________________________________________    A.1   Acetophenone                                                                            Paraformaldehyde                                                                       Sodium sulphite                                                                          --       Acrylic acid                     A.2   Diacetone alcohol                                                                       Formaldehyde                                                                           Sodium sulphite                                                                          Urea     Acrylic acid                     A.3   Cyclohexanone                                                                           Formaldehyde                                                                           Sodium sulphite                                                                          --       Acrylamide/Maleic anhydride      A.4   Acetone   Formaldehyde                                                                           Amidosulphonic acid                                                                      --       Maleic anhydride                 A.5   Acetone   Formaldehyde                                                                           Aminoacetic acid                                                                         Phenol   Styrenesulphonic acid            A.6   Acetylacetone                                                                           Acrolein Sodium sulphite                                                                          --       Methacryloyloxyethyl                                                          phosphate                        A.7   Acetophenone                                                                            Paraformaldehyde                                                                       Sodium sulphite                                                                          --       Acrylic acid/Vinyl acetate       A.8   Diacetone alcohol                                                                       Crotonaldehyde                                                                         Sodium pyrosulphite                                                                      --       Acrylamidopropionicsulphonic                                                  acid                             A.9   Acetone   Crotonaldehyde/                                                                        Sodium sulphite                                                                          --       Itaconic acid                                    Furfurol                                                      A.10  Ethyl methyl ketone                                                                     Crotonaldehyde                                                                         Aminoacetic acid                                                                         --       Acrylamide                       A.11  Mesityl oxide                                                                           Formaldehyde                                                                           Sodium sulphite                                                                          --       Acrylamide                       A.12  Mesityl oxide                                                                           Formaldehyde                                                                           Sodium sulphite                                                                          --       N,N-Dimethylacrylamide           A.13  Mesityl oxide                                                                           Formaldehyde                                                                           Sodium sulphite                                                                          --       N-Vinylpyrrolidone               A.14  Ethyl methyl ketone                                                                     Crotonaldehyde                                                                         Aminoacetic acid    N-Vinylpyrrolidone               A.15  Acetylacetone                                                                           Acrolein Sodium sulphite                                                                          --       Acrolein                         A.16  Diacetone alcohol                                                                       Formaldehyde                                                                           Sodium sulphite                                                                          --       Diallyldimethylammonium                                                       chloride                         A.17  Acetone   Formaldehyde                                                                           Sodium sulphite                                                                          Fe.sub.2 (SO.sub.4).sub.3                                                              Acrylic acid                                                         Na.sub.2 Cr.sub.2 O.sub.7 x2H.sub.2 O     A.18  Mesityl oxide                                                                           Formaldehyde                                                                           Sodium sulphite                                                                          --       N-Vinylpyrrolidone                                                            (Starter: AIBN)                  A.19  Acetone   Formaldehyde                                                                           --         --       N-Vinylpyrrolidone                                                            (Starter: AIBN)                  __________________________________________________________________________

A. Synthesis Examples Example A.1

283.0 parts by weight of water,

118.9 parts by weight of sodium sulphite and

84.9 parts by weight of paraformaldehyde are initially introduced in thestated order in a stirred vessel with an internal thermometer and refluxcondenser and are heated to 60° C.

113.2 parts by weight of acetophenone are added dropwise, slowly anduniformly, to this initially introduced mixture. After introduction ofthe ketone, the solution is stirred for a further 2 hours at 90° C. and,after cooling to room temperature, is adjusted to pH 2 with 50% strengthsulphuric acid.

The yellow reaction solution is heated to 60° C. and air is displacedfrom the stirred vessel by a continuous stream of nitrogen.

5.8 parts by weight of iron(II) sulphate heptahydrate and

45.0 parts by weight of acrylic acid are added at intervals of 30minutes, and after further 30 minutes

2.4 parts by weight of 30% strength hydrogen peroxide solution aremetered in uniformly in the course of 1 minute by means of a peristalticpump. Thereafter, the reaction solution is stirred for a further 2 hoursat 60° C. and, after cooling to room temperature, is rendered neutralwith 35% strength sodium hydroxide solution.

The brown low-viscosity graft polymer solution has a solids content of38% by weight.

Example A.2

119.2 parts by weight of water,

20.0 parts by weight of sodium sulphite,

7.2 parts by weight of urea and

34.6 parts by weight of diacetone alcohol are initially introduced inthe stated order in a stirred vessel with an internal thermometer andreflux condenser and are heated to 60° C.

119.1 parts by weight of 30% strength formaldehyde are added dropwise,slowly and uniformly, to this initially introduced mixture so that thetemperature increases to 90° C. Stirring is carried out at 90° C. for1.5 hours and the mixture is diluted with water as required.

After cooling to room temperature, the viscous solution is adjusted topH 2 with 50% strength sulphuric acid and heated to 60° C. Air isdisplaced from the stirred vessel by a continuous stream of nitrogen.

18.5 parts by weight of iron(II) sulphate heptahydrate,

200.0 parts by weight of water and

14.4 parts by weight of acrylic acid are added at intervals of 30minutes and after further 30 minutes

7.6 parts by weight of 30% strength hydrogen peroxide solution aremetered in uniformly in the course of 1 minute by means of a peristalticpump. Thereafter, the reaction solution is stirred for a further 2 hoursat 60° C. and, after cooling to room temperature, is rendered neutralwith 35% strength sodium hydroxide solution.

The brown, high-viscosity gel has a solids content of 13% by weight.

Example A.3

200 parts by weight of water,

84 parts by weight of sodium sulphite and

98 parts by weight of cyclohexanone are initially introduced in thestated order in succession in a stirred vessel with an internalthermometer and with a reflux condenser and are heated to 30° C. withthorough stirring.

A total of 170 parts by weight of formaldehyde solution (30% strength)is allowed to flow into this initially introduced mixture from a storagevessel, and the temperature should increase from 90° to 95° C. by theend of the introduction of the formalin. After the introduction of theformalin, the solution is kept at 90° to 95° C. for a further 2 hoursand, after cooling to 60° C., is adjusted to pH 2 with 50% strengthsulphuric acid.

The cloudy yellow reaction solution is heated to 60° C., and air isdisplaced from the stirred vessel by a continuous stream of nitrogen.

33.7 parts by weight of iron(II) sulphate heptahydrate,

15.0 parts by weight of acrylamide and

15.0 parts by weight of maleic anhydride are added at intervals of 30minutes and, after a further 30 minutes

13.7 parts by weight of 30% strength hydrogen peroxide solution aremetered in uniformly in the course of 2 minutes by means of aperistaltic pump. Thereafter, the reaction solution is stirred for afurther 2 hours at 60° C. and, after cooling to room temperature, isadjusted to pH 7 with 35% strength sodium hydroxide solution.

The brown, low-viscosity graft polymer solution has a solids content of38% by weight.

Example A.4

246.6 parts by weight of water,

39.9 parts by weight of amidosulphonic acid,

19.3 parts by weight of calcium hydroxide and

47.7 parts by weight of acetone are initially introduced in the statedorder in succession in a stirred vessel with an internal thermometer andreflux condenser and are heated until acetone reflux begins.

A total of 246.6 parts by weight of 30% strength formaldehyde solutionare allowed to flow into this initially introduced mixture from astorage vessel, and the temperature should increase to 90° C. by the endof the introduction of the formalin. After the introduction of theformalin, the solution is kept at 90° C. for a further 24 hours and,after cooling to room temperature, is adjusted to pH 2 with 50% strengthsulphuric acid.

The orange solution is heated to 60° C., and air is displaced from thestirred vessel by a continuous stream of nitrogen.

21.3 parts by weight of iron(II) sulphate heptahydrate and

22.5 parts by weight of maleic anhydride are added at intervals of 30minutes and, after a further 30 minutes,

8.7 parts by weight of 30% strength hydrogen peroxide solution aremetered in by means of a peristaltic pump in the course of 1 minute.

Thereafter, the reaction solution is stirred for a further 2 hours at60° C. and, after cooling to room temperature, is rendered neutral with35% strength sodium hydroxide solution.

The reddish brown, low-viscosity graft polymer solution has a solidscontent of 23% by weight.

Example A.5

161.3 parts by weight of water,

36.9 parts by weight of solid sodium hydroxide,

34.6 parts by weight of aminoacetic acid,

43.4 parts by weight of phenol and

26.8 parts by weight of acetone are initially introduced in the statedorder in a stirred vessel with an internal thermometer and refluxcondenser and are heated until acetone reflux begins.

A total of 138.3 parts by weight of 30% strength formaldehyde solutionare allowed to flow into this initially introduced mixture from astorage vessel, and the temperature should increase to 95° C. by the endof the introduction of the formalin. After the introduction of theformalin, the solution is kept at 95° C. for a further 1 hour and, aftercooling to room temperature, is adjusted to pH 2 with 50% strengthsulphuric acid.

The orange-red reaction solution is heated to 60° C., and air isdisplaced from the stirred container by a continuous stream of nitrogen.

26.0 parts by weight of iron(II) sulphate heptahydrate and 60.0 parts byweight of styrenesulphonic acid, are added at intervals of 30 minutesand, after a further 30 minutes, 11.0 parts by weight of 30% strengthhydrogen peroxide solution are metered in by means of a peristaltic pumpin the course of 1 minute.

Thereafter, the reaction solution is stirred for a further 2 hours at60° C. and, after cooling to room temperature, is rendered neutral with35% strength sodium hydroxide solution.

The dark brown, low-viscosity graft polymer solution has a solidscontent of 34% by weight.

Example A.6

344.3 parts by weight of water,

49.2 parts by weight of acetylacetone and

123.9 parts by weight of sodium sulphite are initially introduced in thestated order in succession in a stirred vessel with an internalthermometer and reflux condenser and are heated to an internaltemperature of 60° C.

A total of 82.6 g of acrolein are added dropwise to this solution. Owingto the highly exothermic reaction, the acrolein is added by a procedurein which the first tenth is added slowly and uniformly and the reactionis then allowed to start, this being evident from the incipient yellowcolour of the initially introduced mixture and vigorous acetone reflux.The remaining 90% of the acrolein are added dropwise with cooling.Stirring is then carried out for 4 hours at 90° C., the reactionsolution becoming deep red.

After the mixture has cooled to room temperature, the pH is adjusted to2 with 50% strength sulphuric acid, the mixture is heated to 60° C. andthe air is displaced from the reaction container by a continuous streamof nitrogen.

13.2 parts by weight of iron(II) sulphate heptahydrate and 30.0 parts byweight of methacryloxyethyl phosphate are added at intervals of 30minutes and, after a further 30 minutes, 5.4 parts by weight of 30%strength hydrogen peroxide solution are metered in uniformly andcontinuously in the course of 1 minute by means of a peristaltic pump.

The reaction solution is then stirred for a further 2 hours at 60° C.and, after cooling to room temperature, is rendered neutral with 35%strength sodium hydroxide solution.

The ochre-colored graft polymer solution has a solids content of 39% byweight.

Example A.7

283.0 parts by weight of water,

118.9 parts by weight of sodium sulphite and

84.9 parts by weight of paraformaldehyde are initially introduced in thestated order in succession in a stirred vessel with an internalthermometer and reflux condenser and are heated to 60° C.

113.2 parts by weight of acetophenone are added dropwise, slowly anduniformly, to this solution so that the internal temperature does notexceed 70° C. After the end of the addition of the ketones, stirring iscontinued for 2 hours at 90° C.

After the mixture has cooled to room temperature, the pH is adjusted to2 with 50% strength sulphuric acid, the reaction solution is heated to60° C. and the air is displaced from the reaction container by acontinuous stream of nitrogen.

57.4 parts by weight of iron(II) sulphate heptahydrate and 15.0/30.0parts by weight of vinyl acetate and acrylic acid are added at intervalsof 30 minutes and, after a further 30 minutes,

22.4 parts by weight of 30% strength hydrogen peroxide solution aremetered in uniformly in the course of 1 minute by means of a peristalticpump.

The reaction solution is then stirred for a further 2 hours at 60° C.and, after cooling to room temperature, is rendered neutral with 35%strength sodium hydroxide solution.

The brown solution has a solids content of 38% by weight.

Example A.8

280.0 parts by weight of water,

22.2 parts by weight of sodium pyrosulphite and

27.2 parts by weight of diacetone alcohol are initially introduced inthe stated order in a stirred vessel with an internal thermometer andreflux condenser and are heated to 70° C.

12.0 parts by weight of sodiumhydroxide and 10.0 parts by weight ofcrotonaldehyde are added to the heated initially introduced mixture. Afurther 88.0 parts by weight of crotonaldehyde are added with cooling,so that the internal temperature does not exceed 70° C. Stirring iscontinued for 30 minutes at 90° C., the mixture is cooled to roomtemperature and the pH is adjusted to 2 with 50% strength sulphuricacid.

The deep red reaction solution is heated to 60° C., and air is displacedfrom the stirred vessel by a continuous stream of nitrogen.

13.6 parts by weight of iron(II) sulphate heptahydrate and

30.0 parts by weight of acrylamidopropanesulphonic acid are added atintervals of 30 minutes, and after further 30minutes

5.6 parts by weight of 30% strength hydrogen peroxide solution aremetered in by means of a peristaltic pump in the course of 1 minute.

The reaction solution is then stirred for a further 2 hours at 60° C.and, after cooling to room temperature, is rendered neutral with 35%strength sodium hydroxide solution.

The brown low-viscosity graft polymer solution has a solids content of34% by weight.

Example A.9

405.9 parts by weight of water,

42.6 parts by weight of sodium sulphite and

39.2 parts by weight of acetone are initially introduced in the statedorder in a stirred vessel with an internal thermometer and refluxcondenser and are heated to 56° C.

A mixture of 64.9 parts by weight of furfurol and 47.4 parts by weightof crotonaldehyde is added dropwise to the initially taken mixture, theinternal temperature being kept at 70° C. by cooling. After the additionof aldehyde is complete, stirring is carried out for 4 hours at 90° C.,the mixture is cooled to room temperature and the pH is adjusted to 2with 50% strength sulphuric acid. The reaction solution is heated to 60°C., and air is displaced from the stirred vessel by a continuous streamof nitrogen.

26.8 parts by weight of iron(II) sulphate heptahydrate,

125.0 parts by weight of water and

37.5 parts by weight of itaconic acid are added at intervals of 30minutes and after further30minutes

10.9 parts by weight of 30% strength hydrogen peroxide solution aremetered in uniformly in the course of 1 minute by means of a peristalticpump.

The reaction solution is then stirred for a further 2 hours at 60° C.and, after cooling to room temperature, is rendered neutral with 35%strength sodium hydroxide solution.

The brown graft polymer solution has a solids content of 27% by weight.

Example A.10

346.3 parts by weight of water,

75.7 parts by weight of crotonaldehyde,

38.9 parts by weight of methyl ethyl ketone and

5.4 parts by weight of potassium carbonate are initially introduced inthe stated order in a stirred vessel with an internal thermometer andreflux condenser and are stirred for 5 hours at 85° C.

52.5 parts by weight of aminoacetic acid and

43.3 parts by weight of water are added to the orange solution and

37.9 parts by weight of crotonaldehyde are added so that the temperatureincreases to 90° C. Stirring is continued for 2 hours at 90° C, and themixture is cooled to 20° C, the pH is adjusted to 2 with 50% strengthsulphuric acid and air is displaced from the stirred vessel by acontinuous stream of nitrogen.

156.4 parts by weight of iron(II) sulphate heptahydrate and

120.0 parts by weight of acrylamide are added at intervals of 30minutes, and after further30minutes

64.0 parts by weight of 30% strength hydrogen peroxide solution aremetered in uniformly in the course of 5 minutes by means of aperistaltic pump.

The reaction solution is stirred for 2 hours at 60° C. and, aftercooling to room temperature, is rendered neutral with 35% strengthsodium hydroxide solution.

The brown graft polymer solution has a solids content of 31% by weight.

Example A.11

17.6 parts by weight of water,

43.1 parts by weight of mesityl oxide and

72.1 parts by weight of sodium sulphite are initially introduced in thestated order in succession in a stirred vessel with an internalthermometer and reflux condenser and are heated to 90° C.

A total of 176.0parts by weight of 30% strength formaldehyde solutionare allowed to flow into this initially introduced mixture from astorage vessel, the temperature being kept at between 90° and 95° C. bycooling until the end of the introduction of the formalin. After theintroduction of the formalin, the solution is kept at 90° to 95° C. fora further hour. In order to keep the reaction solution stirtable, it isdiluted with water as required.

After the reaction solution has cooled to room temperature, the pH isadjusted to 2 with 50% strength sulphuric acid. The deep red reactionsolution is heated to 60° C., and air is displaced from the stirredvessel by a continuous stream of nitrogen.

73.0 parts by weight of iron(II ) sulphate heptahydrate and

186.6 parts by weight of acrylamide are added at intervals of 30minutes, and after a further 30 minutes,

29.8 parts by weight of 30% strength hydrogen peroxide solution aremetered in with cooling in the course of 10 minutes by means of aperistaltic pump.

The reaction solution is then stirred for a further 2 hours at 600° C.and, after cooling to room temperature, is rendered neutral with 35%strength sodium hydroxide solution.

The brown graft polymer solution has a solids content of 21% by weight.

Example A.12

4.6 parts by weight of water,

11.2 parts by weight of mesityl oxide and

18.7.parts by weight of sodium sulphite are initially introduced in thestated order in succession in a stirred vessel with an internalthermometer and reflux condenser and are heated to 90° C.

A total of 45.7 parts by weight of 30% strength formaldehyde solutionare fed into this initially introduced mixture from a storage vessel,the temperature being kept at between 90° and 95° C. by cooling untilthe end of the introduction of the formalin. After the introduction ofthe formalin, the solution is kept at 90° to 95° C. for a further hour.In order to keep the reaction solution stirrable and to dilute thesolution to a solids content of about 5% by weight 637 parts by weightof water are added successively.

After the reaction solution has cooled to room temperature, the pH isadjusted to 2 with 50% strength sulphuric acid. The deep red reactionsolution is heated to 60° C., and air is displaced from the stirredvessel by a continuous stream of nitrogen.

0.10 part by weight of iron(II) sulphate heptahydrate and

36.0 parts by weight of N,N-dimethylacrylamide are added at intervals of30 minutes, and after a further 30 minutes,

4.1 parts by weight of 0.3% strength hydrogen peroxide solution aremetered in by means of a peristaltic pump in the course of 1 minute.

The reaction solution is then stirred for a further 2 hours at 60° C.and, after cooling to room temperature, is rendered neutral with 35%strength sodium hydroxide solution.

The red graft polymer solution has a solids content of 7% by weight.

Example A.13

35.2 parts by weight of water,

86.2 parts by weight of mesityl oxide and

144.1 parts by weight of sodium sulphite are initially introduced in thestated order in succession in a stirred vessel with an internalthermometer and reflux condenser and are heated to 90° C.

A total of 352.0 parts by weight of 30% strength formaldehyde solutionare allowed to flow into this initially introduced mixture from astorage vessel, the temperature being kept at between 90° and 95° C. bycooling until the end of the introduction of the formalin. After theintroduction of the formalin, the solution is kept at 90° to 95° C. fora further hour. In order to keep the reaction solution stirrable, it isdiluted with water as required.

After the reaction solution has cooled to room temperature, the pH isadjusted to 2 with 50% strength sulphuric acid. The deep red reactionsolution is heated to 60° C., and air is displaced from the stirredvessel by a continuous stream of nitrogen.

75.0 parts by weight of iron(II) sulphate heptahydrate and

90.0 parts by weight of N-vinyl-2-pyrrolidone are added at intervals of30 minutes, and after a further 30 minutes,

30.6 parts by weight of 30% strength hydrogen peroxide solution aremetered in by means of a peristaltic pump in the course of 2 minutes.

The reaction solution is then stirred for a further 2 hours at 60° C.and, after cooling to room temperature, is rendered neutral with 35%strength sodium hydroxide solution.

The brown graft polymer solution has a solids content of 40% by weight.

Example A.14

346.3 parts by weight of water,

75.7 parts by weight of crotonaldehyde,

38.9 parts by weight of methyl ethyl ketone and

5.4 parts by weight of potassium carbonate are initially introduced inthe stated order in a stirred vessel with an internal thermometer andreflux condenser and are stirred for 5 hours at 80° C.

Thereafer, 43.3 parts by weight of water and

52.5 parts by weight of aminoacetic acid are added at 80° C. and

37.9 parts by weight of crotonaldehyde are added so that the temperatureincreases to 90° C.

The reaction solution is stirred for 2 hours at 90° C. and, aftercooling to room temperature, is adjusted to pH 2 with 50% strengthsulphuric acid. The reaction solution is heated to 60° C., and air isdisplaced from the stirred vessel by a continuous stream of nitrogen.

18.1 parts by weight of iron(II) sulphate heptahydrate and

266.7 parts by weight of N-vinylpyrrolidone are added at intervals of 30minutes, and after further 30 minutes

7.5 parts by weight of 30% strength hydrogen peroxide solution aremetered in uniformly in the course of 1 minute by means of a peristalticpump.

The reaction solution is then stirred for a further 2 hours at 60° C.and, after cooling to room temperature, is rendered neutral with 35%strength sodium hydroxide solution.

The brown suspension has a solids content of 27% by weight.

Example A.15

344.3 parts by weight of water,

123.9 parts by weight of sodium sulphite and

49.2 parts by weight of acetylacetone are initially introduced in thestated order in a stirred vessel with an internal thermometer and refluxcondenser and are heated to 60° C.

82.6 g of acrolein are added dropwise to this initially taken mixture sothat the temperature does not exceed 70° C. After the addition of thealdehyde is complete, the solution is stirred for a further 4 hours at90° C. and, after cooling to room temperature, is adjusted to pH 2 with50% strength sulphuric acid.

The deep red reaction solution is heated to 60° C., and air is displacedfrom the stirred container by a continuous stream of nitrogen.

37.7 parts by weight of iron(II) sulphate heptahydrate and

45.6 parts by weight of acrolein are added at intervals of 30 minutesand

15.4 parts by weight of 30% strength hydrogen peroxide solution aremetered in uniformly in the course of 1 minute by means of a peristalticpump.

The reaction solution is then stirred for a further 2 hours at 60° C.and, after cooling to room temperature, is rendered neutral with 35%strength sodium hydroxide solution.

The dark brown graft polymer solution of medium viscosity has a solidscontent of 40% by weight.

Example A.16

63.3 parts by weight of water,

63.3 parts by weight of 30% strength formaldehyde solution,

52.4 parts by weight of diacetone alcohol and

4.5 parts by weight of potassium carbonate are initially introduced insuccession, according to Example 1, in the stirred vessel and stirred atan internal temperature of 30° C. for 8 hours.

28.5 parts by weight of sodium sulphite are added to the yellowsolution, which is then heated to 60° C., the solution becoming red.72.1 parts by weight of 30% strength formaldehyde solution are addeddropwise from a storage vessel so that the temperature of the reactionsolution increases to 90° C. After the introduction of the formalin, thesolution is kept at 90° C. for a further hour. In order to keep thesolution stirtable, it is diluted with water as required. The viscoussolution has a solids content of 14.1% by weight.

After the solution has cooled to room temperature, the pH is adjusted to2 with 50% strength sulphuric acid. The deep red reaction solution isheated to 60° C., and air is displaced from the stirred container by acontinuous stream of nitrogen.

0.93 part by weight of iron(II) sulphate heptahydrate and

90.0 parts by weight of diallyldimethylammonium chloride are added atintervals of 30 minutes and, after a further 30 minutes,

3.8 parts by weight of 3% strength hydrogen peroxide solution aremetered in uniformly in the course of 10 seconds by means of a pipette.

The reaction solution is then stirred for a further 2 hours at 60° C.and, after cooling to room temperature, is rendered neutral with 35%strength sodium hydroxide solution.

The red viscous graft polymer solution has a solids content of 18% byweight.

Example A.17

129.1 parts by weight of water,

54.2 parts by weight of sodium sulphite and

39.9 parts by weight of acetone are initially introduced in the statedorder in a stirred vessel with an internal thermometer and refluxcondenser and are heated to 56° C.

As soon as the acetone reflux begins, a total of 258.2 parts by weightof 30% strength formaldehyde solution are added dropwise. Owing to thehighly exothermic reaction, the first tenth of the formalin solution isadded slowly and uniformly. After the reaction has started, which isevident from the incipient yellow color of the initially introducedmixture and increased acetone reflux, the remaining formalin is added,the temperature of the batch being allowed to increase to the boilingpoint. After the addition of the formaldehyde, a 30 minute thermal aftertreatment of the batch at 95° C. is also carried out.

After the solution has cooled to room temperature, its pH is adjusted to4 with acetic acid.

68.6 parts by weight of a 40% strength aqueous iron(III) sulphatesolution are added to the 29% strength resin solution, and the batch isstirred for 2 hours at room temperature, the pH increasing to 8.

For the preparation of the iron-chromium compound, 50.0 parts by weightof a 40% strength aqueous solution of sodium dichromate dihydrate areadded to the solution of the iron compound and stirring is carried outagain for 2 hours at room temperature. The additions of iron salt andchromium salt correspond to an amount of about 5% of iron or chromium,based on resin used. The resulting brown solution of the iron-chromiumcompound has a solids content of 29%. Its Brookfield viscosity is 17mPas at room temperature. The pH of the brown resin solution is reducedto 2 with 50% strength sulphuric acid. The solution is heated to 60° C.,and air is displaced from the stirred vessel by a continuous stream ofnitrogen.

33.7 parts by weight of iron(II) sulphate heptahydrate and

87.3 parts by weight of acrylic acid are added at intervals of 30minutes, and after further 30 minutes 13.7 parts by weight of 30%strength hydrogen peroxide solution are metered in uniformly in thecourse of 2 minutes by means of a peristaltic pump. When the hydrogenperoxide is added, the reaction solution becomes highly viscous.

The reaction solution is stirred for 2 hours at 60° C., diluted with 200g of water and, after cooling to room temperature, neutralized with 35%strength sodium hydroxide solution, with the result that the viscosityof the solution again decreases.

The brown graft polymer has a solids content of 30% by weight.

Example A.18

35.2 parts by weight of water,

86.2 parts by weight of mesityl oxide and

144.2 parts by weight of sodium sulphite are initially introduced in thestated order in a stirred vessel with an internal thermometer and refluxcondenser and are heated to 90° C.

352.0 parts by weight of 30% strength formaldehyde solution are thenadded dropwise uniformly in the course of 10 minutes with cooling. Afterthe addition of the formaldehyde, the solution is stirred for a furtherhour at 90° C. After the solution has been adjusted to pH 10 with 50%strength sulphuric acid, it is heated to reflux and air is displacedfrom the reaction vessel by passing nitrogen through the solution for 30minutes.

A solution of

2.8 parts by weight of 2,2'-azobis-(2-methylpropionitrile) (AIBN) and

180.0 parts by weight of N-vinylpyrrolidone is metered uniformly in thecourse of 20 minutes into the boiling initially introduced mixture bymeans of a peristaltic pump.

The solution is stirred for 3 hours at the boiling point, the viscosityincreasing. After the graft polymer has cooled to room temperature, itis neutralised to pH 7 with 50% strength sulphuric acid.

The red highly viscous polymer solution has a solids content of 49% byweight.

Example A.19

An aldol condensate without an acid function is prepared analogously tothe method according to Houben-Weyl, Volume 14/II, 1963, page 442,Example 3 (a).

696 parts by weight of acetone,

2,178 parts by weight of 30% strength formaldehyde solu- tion and

20 parts by weight of potassium carbonate dissolved in

35 parts by weight of water are initially introduced in the stated orderin a glass beaker.

The clear solution heats up to the boil in the course of 45 minutes. Itis allowed to stand for 26 hours and is then neutralized withconcentrated hydrochloric acid. The colorless solution is thenconcentrated

on a rotary evaporator from a solids content of 17% to about 40% inorder to remove remaining acetone and formaldehyde.

The completely water-soluble resin solution obtained is colorless andhas a Brookfield viscosity of 150 mPas and a solids content of 41.4%.

500 parts by weight of 20% strength aldol condensate solution which wasprepared by the above method are initially introduced in a stirredvessel with an internal thermometer and reflux condenser, adjusted to pH7 with 50% strength sulphuric acid and heated to 90° C. Air is displacedfrom the stirred vessel by a continuous stream of nitrogen.

A solution consisting of 2.9 parts by weight of2,2'-azobis-(2-methylpropionitrile) (AIBN) and 100.0 parts by weight ofN-vinylpyrrolidone is metered uniformly into the initially introducedmixture in the course of 20 minutes by means of a peristaltic pump.

The solution is stirred for 3 hours at 90° C. and diluted with water asrequired. The resulting yellow highly viscous polymer solution has asolids content of 19% by weight.

B. Use Examples B.1 Dispersing Portland Cement

In a dose of 0.5% by weight, based on the cement content, a graftpolymer prepared according to Examples A.3 and A.13 increases the spreadof Portland cement of Class 35 F (water/cement ratio=0.48) by 50% and40%, respectively, at room temperature.

B.2 Dispersing β-hemihydrate Plaster

In a dose of 1% by weight, based on the amount of plaster (302 g ofβ-hemihydrate plaster, 90 g of water and 3 g of graft polymer), a graftpolymer prepared according to Examples A.3 and A.13 increases the spreadby 150% and 100%, respectively, at room temperature. The graftingbackbone (cyclohexanone/formaldehyde/sodium sulphite) for Example A.3,on the other hand, increases the spread of the plaster by only 60%.

B.3 Dispersing Oil Well Cement Slurries

The dispersing action of graft polymers according to the invention inoil well cement slurries is shown in Table 2.

The dose of graft polymers is 1.0% by weight, based on the cementcontent. The cement slurries, consisting of Class H cement and water(water/cement ratio=0.38), are prepared according to the standardconditions of API RP 10 B and were measured using a Fann 35 SAviscometer at 38° C. and four different shear gradients.

                  TABLE 2                                                         ______________________________________                                        Decrease in the viscosity by x% at four dif-                                  ferent shear gradients                                                                     Percentage decrease of the Fann                                               viscosity at rpm                                                 Preparation Example                                                                          600    300       200  100                                      ______________________________________                                        Blank cement slurry                                                                          0      0         0    0                                        A.3            -63    -80       -85  -91                                      A.6            -49    -65       -69  -72                                      A.13           -69    -83       -88  -93                                      ______________________________________                                    

B.4 Dispersing Bentonire Suspensions

Bentonire is used as an additive, inter alia in drilling fluids, forimproving the removal of drill cuttings. However, the drilling fluidmust remain pumpable, that is to say the increase in viscosity due todrill solids must be controlled from time to time by viscosity-reducingadditives. The viscosity-reducing effect of graft polymers according tothe invention in 8% strength by weight of bentonite suspension is shownin Table 3. The measurement of the rheology was carried out at roomtemperature using a Fann 35 SA viscometer.

                  TABLE 3                                                         ______________________________________                                        Decrease (-) or increase (+) in the viscosity                                 of an 8% strength by weight bentonite suspen-                                 sion after the addition of 3% by weight of                                    graft polymer or backbone                                                                Percentage decrease (-) or in-                                                crease (+) of the Fann viscosity                                              at rpm                                                             Preparation Examples                                                                       600    300     200  100   6    3                                 ______________________________________                                        8% strenght by weight                                                                      0      0       0    0     0    0                                 bentonite suspension                                                          A.1          -54    -78     -82  -85   -90  -90                               Backbone A.1 +18    +15     +19  +17   +6   +4                                A.5          -47    -67     -69  -75   -83  -83                               A.7          -51    -56     -58  -58   -58  -58                               Backbone A.7 +18    +15     +19  +17   +6   +4                                A.10         -33    -35     -38  -40   -42  -42                               ______________________________________                                    

B.5 Thickener for Oil Well Cement Slurry

If 1.0% by weight, based on the cement content, of a graft polymerprepared according to A.4 is metered into a Class H cement/water slurry(water/cement ratio=0.38) which is prepared according to the standardconditions of API SPEC 10, the following viscosity-increasing effect canbe measured.

                  TABLE 4                                                         ______________________________________                                        Increase in the viscosity by x% at four dif-                                  ferent shear gradients (38° C.)                                                     Percentage increase of the Fann                                               viscosity at rpm                                                 Preparation Example                                                                          600    300       200  100                                      ______________________________________                                        Blank cement slurry                                                                          0      0         0    0                                        A.4            +21    +23       +24  +37                                      Backbone of A.4                                                                              -26    -45       -50  -54                                      ______________________________________                                    

B.6 Thickener for Bentonite Suspensions

If 3.0% by weight of graft polymer prepared according to A.13 is meteredinto an 8% strength by weight bentonite suspension, the followingviscosity-increasing effect can be measured.

                  TABLE 5                                                         ______________________________________                                        Increase in the viscosity by x% of an 8%                                      strength by weight bentonite suspension                                                  Percentage increase of the Fann                                               viscosity in rpm                                                   Preparation Example                                                                        600    300     200  100   6    3                                 ______________________________________                                        A.13         +38    +38     +37  +31   +24  +24                               ______________________________________                                    

B.7 Flowing Concrete

Graft polymers prepared according to Examples A.3, A.6 and A.13 aresuitable for the production of flowing concrete according to the"Guidelines for the production and processing of flowing concrete" inthe version of May 1974, as cited, for example, in the journal "Beton"24 (1974) on pages 342 to 344.

                  TABLE 6                                                         ______________________________________                                        Increase in the concrete spread by x% at 0.4%                                 by weight dose (based on the cement content)                                              Percentage increase of the                                        Example     spread                                                            ______________________________________                                        A.3         35                                                                A.6         31                                                                A.13        33                                                                ______________________________________                                    

B.8 Bonding of Gas Concrete with Mortar or Cement Paste

Graft polymer prepared according to Example A.2 can be used for thepreparation of mortar or cement paste with high water retention, as, forexample, for the bonding of gas concrete.

The gas concrete is bonded by the cement paste so firmly that no breakoccurs in the joint after 24 hours.

B.9 Inhibition of Swelling of Clays

Cationic graft polymers according to the invention prevent the swellingof clays. If, for example, clay-containing drill cuttings from oil wellsare introduced into a 2% strength by weight aqueous solution of thegraft polymer according to Example A.16, the pieces of the drillcuttings remain intact. No disintegration or increase in volume occurs.In water without the graft polymer according to the invention, the drillcuttings in the form of pieces do undergo swelling. The individualparticles stick together to form a lump which occupies a multiple of theoriginal inherent volume and desintegrates into fine clay particles.

B.10 Retention Agent for Bentonire Suspension

The filtrate water loss of an 8% strength by weight bentoniresuspension, which loss is determined according to the standardconditions of API 13 B-1 (25° C., 0.7 mPa, 30 minutes), can be reducedby adding 3% by weight of graft polymer.

                  TABLE 6                                                         ______________________________________                                        Reduction of the API filtrate water loss of an                                8% strength by weight bentonite suspension                                                   Reduction of the filtrate                                      Preparation Example                                                                          water loss by %                                                ______________________________________                                        A.9            -41                                                            A.13           -33                                                            ______________________________________                                    

It will be understood that the specification and examples areillustrative but not limitative to the present invention and that otherembodiments within the spirit and scope of the invention will suggestthemselves to those skilled in the art.

We claim:
 1. A graft polymer of ketone-aldehyde condensation andco-condensation products and/or monovalent or polyvalent metal compoundsthereof, produced by:(i) grafting an anionic and/or nonionic and/orcationic unsaturated monomer onto a water-soluble condensation product,wherein said condensation product comprises:(a) a symmetrical orasymmetrical ketone containing aliphatic, araliphatic, cyclic oraromatic hydrocarbon radicals with at least one nonaromatic radical; (b)an aldehyde of the formula R--(CHO)_(n), wherein n=1 or 2, and R ishydrogen or an aliphatic, araliphatic, aromatic or heterocyclic radical;and (c) optionally an acid group, said grafting being carried out in anaqueous solution.
 2. The graft polymer of claim 1 wherein said acidgroup is selected from the group consisting of a carboxyl, sulpho,sulphamido, sulphoxy, sulphoalklamine and sulphoalkyloxy group.
 3. Thegraft polymer of claim 1, wherein the total number of carbon atoms andhetero atoms in the ketones is 4 to
 12. 4. The graft polymer of claim 1,wherein the total number of carbon atoms and hetero atoms in thealdehydes is 2 to
 11. 5. The graft polymer of claim 1, wherein the molarratio of ketone:aldehyde:acid group is 1:0.5 to 18:0 to
 3. 6. The graftpolymer of claim 1, wherein the co-condensation components for theketone-aldehyde condensation product are aminoplast formers and/oraromatic compounds or condensation products thereof.
 7. The graftpolymer of claim 6, wherein the aminoplast former consists of urea,melamine, dicyandiamide or a guanamine.
 8. The graft polymer of claim 6,wherein the aromatic compound is a phenol derivative.
 9. The graftpolymer of claim 6, wherein the aromatic compound is a naphthalenederivative.
 10. The graft polymer of claim 1, wherein theco-condensation component for the ketone-aldehyde condensation productis a lignin and/or lignite derivative.
 11. The graft polymer of claim 1,wherein the metal compounds of the condensation and co-condensationproducts contain metals of Group IIA to VIIIA and/or of Group IB to VB.12. The graft polymer of claim 1, wherein the grafted unsaturatedmonomer is anionic and is a vinyl compound containing carboxyl, sulphoor phosphoric acid groups.
 13. The graft polymer of claim 1, wherein thenonionic unsaturated monomer is a vinyl or acrylic derivative.
 14. Thegraft polymer of claim 1, wherein the cationic unsaturated monomer is aquaternary ammonium compound.
 15. The graft polymer of claim 1, whereinthe weight ratio of ketone-aldehyde condensation or co-condensationproduct to unsaturated monomer is 1:0.02 to
 10. 16. A process for thepreparation of a graft polymer comprising:grafting an unsaturatedmonomer onto a ketone-aldehyde condensation or co-condensation productin an aqueous solution at a temperature of 0° to 100° C.
 17. Adispersant for inorganic binder suspensions and solutions, for aqueousclay suspensions and solutions or coal/water suspensions comprising agraft polymer of claim
 1. 18. The dispersant of claim 17 wherein theketone-aldehyde condensation product has a molecular weight of <150,000and a high content of acid groups and/or anionic monomers.
 19. Aretention agent comprising a graft polymer of claim
 1. 20. The retentionagent of claim 19 wherein the retention agent comprises graft polymerson the basis of long-chain ketone-aldehyde condensation products havinga molecular weight of >50,000, the graft polymers having an anionic,non-ionic, or cationic charge.
 21. A thickener comprising a graftpolymer of claim
 1. 22. The thickener of claim 21 wherein the thickenercomprises a graft polymer on the basis of very long-chainketone-aldehyde condensation products having a molecular weightof >75,000, the graft polymers having an anionic, non-ionic, or cationiccharge.
 23. An agent for preventing the swelling of clay in aqueoussystems comprising a graft polymer of claim
 1. 24. The agent of claim 23wherein the agent comprises graft polymers on the basis of short-chainto long-chain ketone-aldehyde condensation products having a molecularweight of 500 to 2,000,000, the graft polymers having a cationic orneutral charge.